German Patent No. 39 36 261 C2 describes a portable computer, called a "laptop computer," that has a display unit which is configured as a flat plate and is arranged rotatably with respect to a base element. A keyboard is permanently installed in the front area of the base element in front of the pivot bearing of the display unit. The computer is equipped with a locking device so that for transport, the display unit can be secured in a position in which it covers the keyboard arranged on the base unit. For operation, the computer is placed on a desk, the lock is opened, and the display unit is swung up into a second position in which it allows operation of the keyboard and viewing of the display unit. With this electronic appliance, therefore, a suitable surface approximately at desk height is always needed for operability.